1/4. Persistence of macroprolactinemia due to antiprolactin autoantibody before, during, and after pregnancy in a woman with systemic lupus erythematosus.A woman with systemic lupus erythematosus (SLE) with marked increases in circulating 150-kDa PRL was studied from before conception, throughout pregnancy, and after pregnancy. The clinical features of the patient included idiopathic hyperprolactinemia without clinical symptoms such as amenorrhea and galactorrhea before pregnancy. No clinical lupus activity was present during follow-up. serum PRL increase during pregnancy in this patient was considerably higher at weeks 27 and 33 than in normal pregnant women. In contrast, serum-free PRL levels were considerably lower at weeks 20, 27, and 33 than in normal pregnant women. A 150-kDa PRL (big big PRL) species persisted as the predominant circulating form of PRL throughout each measurement in this woman with SLE. In contrast, the predominant form of PRL in serum from healthy pregnant women was little PRL (or monomeric PRL). The nature of big big PRL was due to the presence of anti-PRL autoantibodies forming an IgG-23 kDa PRL complex, in accordance with the studies by affinity chromatography for IgG and Western blot analysis. The IgG-PRL complex was fully bioactive in vitro (Nb2 rat lymphoma cell assay). Injection of the serum into the rats demonstrated that the IgG-PRL complex was cleared more slowly than serum containing predominantly monomeric PRL. The data suggest that the IgG-PRL complex has biological activity; the absence of symptoms in this woman may be attributed to the fact that due to its large molecular weight, big big PRL does not easily cross the capillary walls. Delayed clearance may account for increased serum PRL levels in this SLE patient with anti-PRL autoantibodies.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
2/4. Concomitant occurrence of macroprolactin, exercise-induced amenorrhea, and a pituitary lesion: a diagnostic pitfall. Case report.The authors report the case of a 37-year-old woman who presented with amenorrhea and an increased level of serum prolactin. Magnetic resonance images of the pituitary revealed a lesion with characteristics consistent with those of a microadenoma. Transsphenoidal exploration was performed, but a prolactinoma was not found. After endocrinological review, the patient's hyperprolactinemia was found to be caused by the presence of macroprolactin and her amenorrhea was due to intense exercise and low body weight. Macroprolactin is an isoform of prolactin that is variably reactive in assays for prolactin, but displays minimum bioactivity in vivo. patients with macroprolactin are mostly asymptomatic. This phenomenon may cause elevated prolactin values, which the authors view as apparent hyperprolactinemia. The presence of macroprolactin is an underrecognized problem, occurring in as many as 15 to 20% of patients with elevated prolactin values and often leading to unnecessary, expensive diagnostic procedures and inappropriate treatment. The presence of macroprolactin should always be suspected when the patient's clinical history or clinical or radiological data are incompatible with the prolactin value. physicians dealing with diagnosis and treatment of hyperprolactinemia (general practitioners, gynecologists, neurosurgeons, endocrinologists, and biochemists) should be aware of the potentially misleading nature of macroprolactin.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
3/4. On the nature of serum prolactin in two patients with macroprolactinemia.OBJECTIVE: To further characterize the high molecular weight (MW) forms of prolactin (PRL) present in patients with macroprolactinemia. DESIGN: case reports with laboratory investigations. SETTING: academic medical centers. patients: Two patients with macroprolactinemia. INTERVENTIONS: Measurements of PRL concentrations before and after chromatographic separations. RESULTS: The majority of serum PRL had an estimated MW of at least 669 kd in the first patient and approximately 171 kd in the second. During a pregnancy, a new form of PRL (MW 291 kd) appeared in the first patient's serum and persisted for at least 3 years. immunoprecipitation and polyacrylamide gel electrophoresis under reducing and denaturing conditions revealed that the largest form of PRL (MW 669 kd) was composed mostly of 25 kd glycosylated PRL; intermediate forms (171 kd and 291 kd) were composed of roughly equal portions of 25 kd glycosylated PRL and 23 kd nonglycosylated PRL, whereas "little" PRL in these patients was composed primarily of 23 kd nonglycosylated PRL. Injection of the first patient's serum into rats demonstrated that the human PRL (hPRL) immunoreactivity was cleared from the serum more slowly than the PRL from sera containing predominantly little hPRL; after stimulation with thyrotropin-releasing hormone in the second patient, serum PRL concentrations decayed more slowly than observed in normal subjects. CONCLUSIONS: Large forms of serum PRL are at least partially glycosylated. These large forms are heterogeneous, both within and among patients. Delayed clearance may account for increased serum PRL concentrations in patients with macroprolactinemia.- - - - - - - - - - ranking = 4keywords = nature (Clic here for more details about this article) |
4/4. Reversible weight gain and prolactin levels--long-term follow-up in childhood.In adult patients weight gain is a frequent complaint of hyperprolactinaemia and it has been associated with a high prevalence of obesity. Normalization of prolactin (PRL) levels result in weight loss. The nature of this link is poorly defined. In this report we describe a 14 year-old female with primary amenorrhea and persistent progressive weight gain. The patient's height, weight and BMI were 152 cm, 70 kg, and 30.3 kg/m2, respectively. Basal hormonal investigation showed normal free thyroxin, TSH, IGF-I, cortisol and ACTH values. serum PRL level was very high (16,278 mIU/l; normal range 63-426 mIU/l). magnetic resonance imaging scan showed the presence of a pituitary microadenoma. Treatment with the non-selective dopamine agonist pergolide caused a significant reduction of serum PRL concentration with a remarkable decrease of body weight. During follow-up, repeat MRI scan revealed disappearance of the microadenoma. The reduction of the daily dose of pergolide was associated with an increase of serum PRL with significant weight gain. A further reduction of body weight was subsequently observed with an increase of pergolide dosage. serum PRL measurement may be useful as part of the endocrine work-up of obese children with a history of unexplained recent weight gain, especially if associated with pituitary-gonadal axis dysfunction. The relationship between PRL secretion and weight change needs to be examined in prospective larger studies.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |